Statistically Speaking

Wednesday, February 28, 2007

Big 12 Rewind: SDPI

Before getting into the Big 12, head over to The Power T Blog. Doug's doing some stat work of his own, starting with the SEC.

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all Big 12 teams in conference play (championship game not included) was 210.083 points. The standard deviation for points scored was 42.98. The standard deviation for points allowed was 52.14. Nebraska scored 236 and allowed 173 points. Nebraska's offensive SDPI was 0.60 = ([236-180.083]/42.98). Their defensive SDPI was 0.71 = ([210.083-173]/52.14). Their total SDPI was 1.31. In the 2006 Big 12, that was good for third best.

Their two late season losses to Kansas State and Texas A&M cost the Longhorns a shot to win the Big 12. The top two and four of the top six teams were in the Big 12 South.

Best Offense: Texas 1.39Freshmen Colt McCoy did his part to help keep the Longhorns at the top of the Big 12 heap.

Worst Offense: Iowa State -2.10Despite returning their starting quarterback, running back, and leading receiver the Cyclones struggled mightily in Dan McCarney's final season. They broke the 20 point barrier only twice in conference play (Missouri and Texas Tech).

Best Defense: Oklahoma 1.71Sooners had the league's best defense. A good thing because their offense was actually below average.

Worst Defense: Baylor -2.11After they opened conference play holding Kansas State to 3 points, the Bears allowed at least 30 points in their next 7 conference games. Three teams broke 50 and two (Texas and Oklahoma State) broke 60.

Best Team that Didn't Go to a Bowl: Kansas 0.27The Jayhawks did get to bowl eligibility at 6-6, but were not selected for postseason play. According to SDPI, they were the 7th best team in the conference, just a notch below Texas A&M.

Worst Team that Went to a Bowl: Kansas State -0.67Aided by a 3-0 record in close games (2-0 in conference play) the Wildcats went bowling for the first time since 2003.

Toughest Schedule (ranked by sum of opponent's SDPI): Iowa State 4.66The Cyclones drew both of the behemoths from the South (Texas and Oklahoma) and avoided Baylor.

Easiest Schedule (ranked by sum of opponent's SDPI): Kansas -4.26The Jayhawks avoided Texas and Oklahoma from the South and drew Baylor (who they lost to).

Team(s) Likely to Decline: Kansas State and Texas A&MThe Wildcats won 7 games last season thanks to luck (3-0 in close games) and great special teams play. Their offense and defense were both below average in Year One of the Ron Prince Era. Check the stats. Twice as many interceptions as touchdown passes? Allowed 58% of passes to be completed? The return game bailed these guys out a lot last season. Punt and or kickoff return touchdowns were the difference in the narrow victories over Illinois State and Oklahoma State. Relying on the return game to be as phenomenal as it was last year is a lot to ask. Couple some special teams regression with a tougher non-conference schedule (at Auburn, at Fresno State, and a home date with feisty San Jose State) and the Wildcats will very likely be spending the holidays in Manhattan. Seven of Texas A&M's eight conference games were decided by 6 points or less. The Aggies went 4-3 in those games. Any regression in the luck department and the Aggies could be looking down only at Baylor in the Big 12 South.

Team(s) Likely to Improve: Missouri, Kansas, and Oklahoma StateOnly 6 on the conference's 12 teams have played in the Big 12 Championship Game: Nebraska, Colorado, and Kansas State from the North and Oklahoma, Texas, and Texas A&M from the South. That could change this season as these three teams should all improve. Missouri returns their terrific quarterback Chase Daniels and gets their biggest division foe Nebraska at home while avoiding at least one of the Southern Giants (Texas). Kansas also gets the Huskers at home and avoids both Oklahoma and Texas while once again drawing Baylor. Despite their 3-5 conference record last season, SDPI sees the Cowboys as the 5th best team in the conference. They were a tough luck 0-4 in close games in conference play. In 2007, their high powered offense returns both the starting quarterback, Bobby Reid, and his leading receiver Adarius Bowman. The Cowboys do draw two of the stronger teams from the North (Nebraska and Kansas), but if the 8-year reign of Sooner/Longhorn terror is to end in the South in 2007, the Cowboys will be the team to do it.

Saturday, February 24, 2007

SEC Rewind: SDPI

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all SEC teams in conference play (championship game not included) was 166.83 points. The standard deviation for points scored was 36.46. The standard deviation for points allowed was 33.20. Arkansas scored 221 and allowed 134 points. Arkansas' offensive SDPI was 1.49 = ([221-166.83]/36.46). Their defensive SDPI was .99 = ([166.83-134]/33.20). Their total SDPI was 2.47 (difference due to rounding). In the 2006 SEC, that was good second, just a hair behind LSU.

Most folks will take one look at those numbers and immediately become close-minded since the third place team not only won the conference, but also the national championship. But remember, the Gators survived both Tennessee and South Carolina by one point apiece, Georgia by 7, and Vandy by 6. With a few bounces going the other way, the Gators historic season could have ended in the Outback Bowl.

Best Offense: Arkansas 1.49The tandem of McFadden and Jones took the SEC by storm despite inconsistent play from the quarterback position.

Worst Offense: Mississippi -1.20Even with Michael Oher, from The Blindside, a great book if you need some reading material, the Rebel offense struggled mightily. They broke 20 points only once in conference play--against Alabama.

Best Defense: Florida 1.29Defense wins championships? Maybe so. Before the SEC Championship Game (which is not included) only one team broke 20 against them and that was on a defensive touchdown in the games final seconds.

Worst Defense: Mississippi State -1.66Held two teams under 20 points, South Carolina and Alabama. Incidentally, the game against Alabama was their only win.

Best Team that Didn’t Go to a Bowl: Mississippi -1.66This says more about the conference than the Rebels. When 9 of the conferences 12 teams play in the postseason, the teams that don't are usually pretty bad.

Worst Team that Went to a Bowl: Kentucky -1.32The Wildcats were only marginally better than Mississippi, but benefited from the scheduling gods--two of their games against the SEC West were against dregs Mississippi and Mississippi State, and a close win over Georgia.

Toughest Schedule (ranked by sum of opponent’s SDPI): Tennessee 2.44In their SEC West games, the Vols played the league's two best team (LSU and Arkansas) and Alabama while avoiding the weaker sisters (Mississippi and Mississippi State).

Easiest Schedule (ranked by sum of opponent’s SDPI): Georgia -4.30Like Kentucky, they played the SEC West's two weakest teams (Mississippi and Mississippi State) and an Auburn team that was substantially worse than the West's top two teams.

Team(s) Likely to Decline: Kentucky, Arkansas, and LSUThe Wildcats were not nearly as good as their 4-4 conference record would portend. In 2007, only one of their home games looks winnable (Mississippi State). The others are against LSU, Florida and Tennessee. Their road games are against Arkansas, South Carolina, Vanderbilt, and Georgia. Kentucky will probably finish in the SEC East cellar. Unless Arkansas gets some much improved play from quarterback Casey Dick, expect the Hogs to fall to the middle of the pack in the SEC West. McFadden and Jones are still on the team, but the Hogs attack can't be as one-dimensional as last season if they want to get back to the SEC Championship Game. And don't forget about all the offseason drama--complete with forwarded emails, impromptu resignations, parental meetings, and transfers. Don't buy into the LSU=National Champion hype. The Tigers lost a key cog to their offense--JaMarcus Russell. As noted here and here, losing your starting quarterback hurts more than bringing him back helps.

Team(s) Likely to Improve: Alabama and South CarolinaThe Tide were only 2-4 in close conference games last season so expect some improvement in that department. They return a very competent starting quarterback in John Parker Wilson. And some guy named Saban is now coaching the team. Saban will probably get too much credit for the turnaround as Bama had a lot of positive indicators for an improvement even if Shula remained the coach. Check the schedule too. Vandy, Mississippi, and Mississippi State as three of the four conference road games. Four tough teams (Arkansas, Georgia, Tennessee, and LSU) do come to Bryant-Denny, but the schedule is built for Bama to win the SEC West. Initially, I though South Carolina had a chance to win the East, what with Spurrier being in his third season with a stellar recruiting class. The schedule is just too tough to send the Gamecocks to Atlanta. Roadies at Georgia, LSU, Tennessee, and Arkansas and a home date with Florida is a lot to overcome. Their other three home games are likely wins (Mississippi State, Kentucky, and Vandy), so they will definitely improve on their 3-5 conference mark.

Monday, February 19, 2007

Big 10 Rewind: SDPI

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all Big 10 teams in conference play was 186 points. The standard deviation for points scored was 52.90. The standard deviation for points allowed was 70.08. Penn State scored 135 and allowed 117 points. Penn State's offensive SDPI was -0.96 = ([135-186]/52.90). Their defensive SDPI was .98 = ([186-117]/70.08). Their total SDPI was 0.02. In the 2006 Big 10, that was good for fourth best.

The 2006 Big 10 was the epitome of football stratification. Ohio State, Wisconsin, and Michigan were head and shoulders above the rest of the league. In fact, the difference in SDPI between Michigan (3rd best) and Penn State (4th best) was greater than the difference between Penn State and Michigan State (9th best).

Best Offense: Ohio State 2.25Before he melted down in the BCS Championship Game, Troy Smith was a beast in Big 10 play, throwing 20 touchdown passes and just 5 interceptions en route to winning the Heisman. Of course, don't forget the other fabulous skill position players: Antonio Pittman, Ted Ginn Jr., and Anthony Gonzalez to name a few.

Worst Offense: Northwestern -1.15After averaging 31.6 points per game in Big 10 play in 2005, the Wildcats averaged only 15.6 per game in 2006. Only 3 times did they score more than 10 points (Michigan State, Iowa, and Illinois). Perhaps not coincidentally, they won two of those games.

Best Defense: Ohio State 1.34Gave up only 92 points in conference play, with 39 coming in the season finale against Michigan.

Best Team that Didn’t Go to a Bowl: Illinois -1.07Despite finishing in the Big 10 cellar, the Illini were actually the 8th best team in the conference.

Worst Team that Went to a Bowl: Minnesota -0.51After a miserable start in Big 10 play (0-5 and outscored by an average of over 20 per game), the Gophers won their final 3 (all by at least 10 points) to become bowl eligible.

Toughest Schedule (ranked by sum of opponent’s SDPI): Northwestern 4.22Wildcats played the top 6 SDPI teams in the conference and 8 of the top 9. Only way the schedule could have been tougher would be to replace Michigan State with Minnesota.

Easiest Schedule (ranked by sum of opponent’s SDPI): Ohio State -5.40Played the bottom 6 SDPI teams and avoided Wisconsin. However, their schedule rating is so low primarily because they didn't have to play themselves. Dominated the league, so take their schedule rating with a grain of salt.

Team(s) Likely to Decline: Ohio State, Purdue, and IndianaBuckeyes simply lose too much to repeat as Big 10 champs. Have to go on the road to Michigan and Penn State in 2007. Every 3 years, Buckeyes seem to fall down a notch--2001 7-5 before consecutive 11+ win seasons, 2004 8-4 before consecutive 10+ win seasons. Time for the Boilermakers to pay the piper. After avoiding Michigan and Ohio State in 2005 and 2006, while compiling only 5-6 and 8-6 records, the Boilers get them both to go along with tough road games at Penn State and Minnesota. Hoosiers actually finished tied for 6th in the Big 10 with 3 conference wins, but according to SDPI were actually only better than Northwestern. Despite nearly becoming bowl eligible, Hoosiers have farther to go than most observers believe.

Team(s) Likely to Improve: Illinois and Michigan StateThe Illini had terrible luck in close games last season (1-4) and were actually the 8th best team in the conference. Couple that with a few strong recruiting classes and the Zooker will have them back in a bowl game for the first time since their Sugar Bowl appearance in 2001. Spartans were also a tough luck 1-4 in close games so expect some improvement in that area. Also not coached by a complete maniac so they have that going for them.

Tuesday, February 13, 2007

Big East Rewind: SDPI

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all Big East teams in conference play was 172.25 points. The standard deviation for points scored was 58.22. The standard deviation for points allowed was 37.97. Cincinnati scored 152 and allowed 141 points. Cincinnati’s offensive SDPI was -0.35 = ([152-172.25]/58.22). Their defensive SDPI was .82 = ([172.25-141]/37.97). Their total SDPI was 0.48 (not 0.47 because the other two were rounded). In the 2006 Big East, that was good for fifth best.

Best Offense: West Virginia 1.49Pat White, Steve Slaton, and Mountaineers’ spread option were the best offense in the Big East.

Worst Offense: Syracuse -1.57The most points they scored in conference play was 20. Held to 17 or less in their other 6 conference games.

Best Defense: South Florida 1.03Held every opponent except Louisville to 20 points or less.

Worst Defense: Connecticut -1.73All you need to know: The Orangemen scored 20 on their defense.

Best Team that Didn’t Go to a Bowl: Pittsburgh -0.92This says more about Pitt’s non-conference slate than anything (Citadel). Lost their last 5 games to finish 6-6.

Worst Team that Went to a Bowl: Cincinnati 0.48Hardly an indictment of their team as the Bearcats had a solid season that included a near miss against Louisville and beatdowns of South Florida and undefeated Rutgers.

Schedule Strength: No need to rank schedule strength since everybody plays everybody in the 8-team league.

Team(s) Likely to Decline: Pittsburgh and LouisvilleThe Panthers can’t blame lousy luck in close games like they could in 2005 for their sub-par record. The Panthers couldn’t post bowl bids in Wanny’s first two years with Tyler Palko, so chances are they won’t in the first year AP. The Cards should be good yet again, but losing Petrino will hurt, as will road trips to West Virginia, South Florida, and Cincinnati.

Team(s) Likely to Improve: South Florida and SyracuseAs long as Matt Grothe stays healthy the Bulls will be a sleeper team in the Big East. They get the two big boys (West Virginia and Louisville) as well as Cincinnati at their place. Despite their offensive struggles, Syracuse was actually not the worst team in conference play last year. If their offense improves at all (and it may with Perry Patterson graduating) the Orangemen could finish a little higher in the standings.

Thursday, February 08, 2007

ACC Rewind: SDPI

One way to look at team strength, taken from Eddie Epstein’s fantastic book Dominance, is to look at teams points scored and allowed relative to the league average and standard deviation. The more standard deviations they are from the mean, the better (or worse they are). For those unfamiliar with what standard deviation is here’s the wikipedia link. In the coming weeks, I will be looking at each Division IA conference and ranking each team in regards to their Standard Deviation Power Index in conference play. Keep in mind, the SDPI does not adjust for schedule strength for conferences such as the ACC where each team does not play each other and it ignores special teams which can play a significant role in both points scored and points allowed.

If you want the meat of the article, skip this next paragraph as it just gives an example of how the SDPI is calculated. The mean points scored and allowed for all ACC teams in conference play (championship game not included) was 162 points. The standard deviation for points scored was 35.97. The standard deviation for points allowed was 51.18. Coastal Division champ Georgia Tech scored 213 and allowed 155 points. Georgia Tech’s offensive SDPI was 1.42 = ([213-162]/35.97). Their defensive SDPI was .14 = ([162-155]/51.18). Their total SDPI was 1.55 (not 1.56 because the other two were rounded). In the 2006 ACC, that was good for third best.

If you thought Wake Forest was doing it with smoke and mirrors, well you were probably right. SDPI has Wake Forest as an above average, but middling team (5th place in the league). The league’s best team, according to SDPI, did not get to participate in the title game thanks to their mid-season struggles. Although 3 of the 4 Tobacco Road schools finished with at least 6 losses, its clear North Carolina and Duke were in a league of their own in terms of ineptitude.

Best Offense: Georgia Tech 1.42Despite the best efforts of Reggie Ball the Yellow Jackets did post the league’s best offensive SDPI.

Worst Offense: North Carolina -1.47Yes they were worse than Duke.

Best Defense: Virginia Tech 1.35In their last 4 conference games, the Hokies gave up 23 points.

Worst Defense: Duke -2.31Held only one team to under 20 points (Wake Forest) and still lost thanks to a blocked field goal. Interestingly, the best and worst from each category all came from the Coastal Division.

Best Team that Didn’t Go to a Bowl: Virginia -0.15The Cavs were 4-4 in the ACC (about what you would expect given the almost average ranking), but failed to go bowling thanks to a 1-3 mark in non-conference play.

Worst Team that Went to a Bowl: Maryland -0.45All 5 of their conference wins came by 6 points or less, including two by a single point, one by two, and one by three.

Toughest Schedule (ranked by sum of opponent’s SDPI): Maryland 4.42Maybe that’s why they played so many close games. No Hokies, but also no Heels or Devils on the schedule.

Easiest Schedule (ranked by sum of opponent’s SDPI): Georgia Tech -3.98Jackets had the easiest schedule and won their division. Coincidence? Played the Atlantic’s best (Clemson), but also the two worst (Maryland and NC State).

Team(s) Likely to Decline: Wake Forest and MarylandThe Deacs are not going to win the ACC again next year obviously, but should be competitive and go to a mid-level bowl game. Maryland’s unbelievable luck in close games will not continue and don’t be shocked to see The Fridge’s boys in the Atlantic basement next season.

Team(s) Likely to Improve: Virginia and NC StateThe Cavs were a very young team in 2006, but were still actually about average. Expect 2007 to be Groh’s best in Charlottesville. NC State finished 2-6, but they were much closer to Maryland in terms of SDPI than either of their basement brethren on Tobacco Road. Tom O’Brien was a great hire and NC State will contend for a bowl game in 2007.

Sunday, February 04, 2007

Super Bowl Thoughts

Even though this has evolved into a college football blog, it's the Super Bowl. So for those who care, these are my thoughts.

1. Even though the Bears played in the weaker conference, people still seem to forget they had a better record (13-3 versus 12-4) and a better point differential (+172 versus +67) than the Colts.

2. The Colts were 10-0 in the RCA Dome this season, but a more pedestrian 5-4 away from home. This game is not at Soldier Field, but the Colts chances of winning are much closer to 56% than 100%. The Bears were 7-1 on the road if you were wondering.

3. The Bears defense has not been the same since the Tommie Harris injury in game 12. In the first 12 games they gave up 12.5 points per game. In the last six they have given up 23.8 per game.

4. The Colts defense that has played reasonably well in the playoffs (very well before the New England game) still got shredded for 173 yards per game on the ground and allowed an average of 5.33 yards per carry.

5. Peyton Manning is a better quarterback than Rex Grossman. John Elway was better than Doug Williams. Fran Tarkenton was better than Ken Stabler. Roger Staubach was better than Terry Bradshaw. Jim Kelly was better than both Jeff Hostetler and Mark Rypien. 52 other guys on each team will have a say in how this game turns out.

6. The Colts coverage units are awful. Their punt coverage units finished 31st in the league allowing 13.1 yards per return. Their kickoff coverage was not much better ranking 30th while allowing 26 yards per runback. Chicago led by Devin Hester, finished 2nd in punt return average (12.1 per return) and 8th in kickoff return average (23.3). And remember, the last time a special teams player won the Super Bowl MVP, his initials were also DH.

While the Bears may not win this game, odds are they will be very competitive. That 7 point spread is a lot to lay if you're a Colts backer. Here's my prediction. I won't give you a winner, but I'll take the Bears +7 any day.

Saturday, February 03, 2007

Does the Better Team Usually Win Close Games?

I'm taking a brief sabbatical from the quarterback question (I'll have the splits for BCS versus non-BCS teams shortly) and focusing on an old reliable: close games. What I want to know is: How often (at least in 2006) did the 'better' team win a close ball game (decided by 8 points or less)? Now defining better will get you in a ton of trouble, but I've decided to try and do it anyway. For the purpose of this analysis, I'm looking at each team's record outside the game in question. Now of course, this ignores schedule strength and a host of other variables including when the game was played. Some teams improved dramatically over the course of the season (Arkansas and Wake Forest) and some teams fell apart (Clemson). Still, its a quick and easy measure and it can tell us a little something about team strengths. If the teams have the same record outside of their close game then it gets ignored. For example, in a Week 1 game that broke the TV ratings record set by M*A*SH, Buffalo beat Temple 9-3 in overtime. Buffalo finished the season 2-10, while Temple finished 1-11. Outside of that game, both teams were 1-10, so they are treated as being roughly equal and the game is not counted. In addition, the team's record outside of the close game must be more than 1/2 a game different, in order to adjust for the varying season length of each team's schedule which can include bowl, conference title, and/or Hawaii games. For example, in mid-October, Alabama beat Ole Miss 26-23. Alabama finished the season 6-7 after losing their bowl game. Ole Miss did not play in a bowl game and finished 4-8. Outside of their game against each other, Alabama was 5-7 and Ole Miss was 4-7. Since the difference is only 1/2 game, this game is also ignored and the teams are treated as equals.

In 224 games decided by 8 points or less. where there was at least a game difference between the teams outside of the close game, the 'better' team had a cumulative record of 139-85. The 'better' team won a close game a little more than 62% of the time in 2006. That seems like a pretty strong majority, and it would be in a presidential elections. But look at it the other way. The weaker team has a 38% chance (better than 1 in 3) of pulling off the upset. Most underdogs would gladly take those odds.

Finally, here's a theoretical example. Say your a pretty good team in a BCS conference. Let's go ahead and assume your the best team in your BCS conference. But your conference is very strong (say like the SEC in 2006) and you have to play three teams, that while a notch below you are still pretty good. And each of those games turns out to be a nail-biter. The odds that you win everyone of those games is just 23.9% (.62 ^3). And what about that road game against a decent team where you took them lightly and they played you tight deep into the fourth quarter. Odds that you win all 4? 14.8% (.62 ^4). The point I'm trying to hammer home yet again, is that close games have a lot to do with lady luck. Even when you are the better team, the fates can intervene and hand you a close loss.